The rights from the family to build the course? What does that mean? They have rights to implement that design anywhere on earth in perpetuity? I’m sure David Edel wants folks to believe that’s the case.
From the 2009
Thomas Dunne article, the original agreement with David Edel had many use stipulations, including an execution timeline and name use rights.
You probably need someone with knowledge of copyright law to answer but MacKenzie published, or had published, a number of plans in Golf Illustrated UK and i think off the top of my head that El Boqueron might have been one. That, and the fact that Mac died more than 70 years ago probably has some bearing I'd have thought.
I don't think I've seen El Boqueron reference prior to the Thomas Dunne article, MacKenzie didn't not list the course as one of his designs in the Spirit of St. Andrews.
It would seem MacKenzie being dead more than 70 years would have no bearing on this matter, as the plan to the course has been privately owned since its commission.
It is an interesting question. If I was to build a Frank Lloyd Wright house today would that be considered infringement?